1. Field of the Invention
The present invention relates to a novel saccharide, and its preparation and uses, more particularly, it relates to lactoneotrehalose shown by the formula O-.beta.-D-galactopyranosyl-(1.fwdarw.4)-O-.beta.-D-glucopyranosyl .alpha.-D-glucopyranoside, and its preparation and uses.
2. Description of the Prior Art
Lactose, which is shown by the formula O-.beta.-D-galactopyranosyl-(1.fwdarw.4)-D-glucose, has been known for long as a sweet saccharide present in milk of mammals. Recent increment in the production of milk products such as butter and cheese has been accompanied with a large amount of lactose as by-product. The reducing properties, susceptivity to the browning reaction and low solubility in solvents of lactose have restricted its use of lactose only to the preparations of chocolate, chewing gum and tablet.
Actually, the production of lactose has exceeded the consumption and this resulted in an excessive stock of lactose, as well as having suppressed the production of lactose.
Various attempts have been made to obtain novel saccharides wherein these properties and demerits of lactose are improved.
For example, Bailey et al. reported in Nature, Vol.176, pp.1164-1165 (1955) their finding that O-.beta.-D-galactopyranosyl-(1.fwdarw.4)-O-[.alpha.-D-glucopyranosyl-(1.fw darw.2)]-D-glucopyranose was formed when microorganisms of the species Batacoccus arabinosaceous were cultured a medium containing lactose and sucrose: Okada et at. disclosed in Japanese Patent Laid-Open No.98,093/73 a method to prepare reducing oligosaccharides which comprises subjecting lactose and partial starch hydrolysate to the action of saccharide-transferring enzymes to allow a glucosyl residue from partial starch hydrolysate to the galactosyl residue of lactose; and Igarashi et at. disclosed in Japanese Patent Laid-Open No.205,793/87 a method to prepare O-.alpha.-D-glucopyranosyl-(1.fwdarw.3)-O-.beta.-D-galactopyranosyl-(1.fwd arw.4)-D-glucose which contains a step of subjecting lactose and partial starch hydrolysate to the action of .alpha.-glucosidase from buckwheat or rice.
The saccharides disclosed in the prior art, however, are all reducing-oligosaccharides which are susceptive to the browning reaction and never improve the drawbacks of lactose.